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La mer d'Aral en Asie centrale fut autrefois la quatrième plus grande mer fermée du monde. Elle couvrait une surface de 67'499 km² entre le Kazakhstan et l'Ouzbékistan. Sa surface a été réduite de 80 % en seulement 50 ans en raison de l'irrigation croissan ...
We describe a concept for a novel stationary solar concentrator that relies on a new self-adaptive optical valve, non-imaging optics and the integrating sphere principle. Our analytical model reveals that this unique combination theoretically allows reachi ...
Asian knotweeds (Fallopia spp.) are considered one of the world's most invasive species. Restoring habitats dominated by these exotic species requires a better understanding of the importance of abiotic factors controlling the invasive knotweeds performanc ...
The present thesis deals with luminescent compounds based on lanthanide complexes that are suitable for color reproduction and optical document security with invisible luminescent inks. This thesis is divided in two distinct fields: chemistry, which produc ...
A theoretical approach based on coupled-mode theory is presented in order to determine the radiation pattern of LEDs incorporating a shallow photonic crystal. From this, a fundamental limit for the directionality of the diffraction of a single guided mode ...
Thin-film InGaN photonic crystal (PhC) light-emitting diodes (LEDs) with a total semiconductor thickness of either 800 nm or 3.45 mu m were fabricated and characterized. Increased directional radiance relative to Lambertian emission was observed for both c ...
The appearance of real world objects is the result of the combination of their own texture and the light rays striking them before reaching our eyes, or our camera. This appearance therefore brings very rich information about the objects shapes, materials, ...
This work discusses solar power towers and especially the simulation and optimization of heliostat fields. The technological stateof the art is given through typical characteristic values and dimensions of some existing central tower power plants such as t ...
Limitations in extraction efficiency of gallium nitride (GaN) photonic crystal (PhC) light emitting diodes (LEDs) are addressed by implementing an LED design using both two-dimensional PhCs in-plane and index guiding layers (IGLs) in the vertical direction ...
We study the fate of the surface states of Bi2Se3 under disorder with strength larger than the bulk gap, caused by neon sputtering and nonmagnetic adsorbates. We find that neon sputtering introduces strong but dilute defects, which can be modeled by a unit ...
